BILT Speaker

BILT Speaker
RevitCat - Revit Consultant

Friday 31 July 2015

RTC Asia - The Best Tall Building in the World Needs lots of Multistorey Stairs

This year I will be presenting two sessions at RTC Asia 2015 at the Singapore.  I hope to see you all in Singapore from 10 - 12 September 2015 for the inaugural Asian Revit Technology Conference - for all things BIM in the construction industry.

The first session will be 'The Best Tall Building in the World - Documented in Revit' describing the trials and tribulations we went through in Revit to document the project 'One Central Park' in Sydney.  I will be describing the building itself and some of the techniques that we used to handle construction documentation for such a large and complex building in Revit starting six years ago (completed in 2013, and given the 'Best Tall Building Worldwide' award in 2014).
One Central Park cantilevered heliostat mirrors
This presentation will be one of the first sessions after the keynote speaker.  You will get to see lots of photos of the building inside and outside;  and you will hear about the massive cantilever 29 storeys up in the air.

Stairway to Heaven 

I will also be running a Lab Session  titled 'Stairway to Heaven'

This session will look at ways of making the new Stair & Railing tools in Revit work better for you.  It will start you off on the 'Stairway to Heaven' instead of languishing in the 'Stair & Railing Hell' that most Revit users live in.*   We will be covering such topics as multistorey stairs and railings, winder stairs, stair sketches.

* Disclaimer:  The aims stated above are of course restricted by the limitations of Revit software.

With thanks to the artist who designed this image for Led Zeppelin

Monday 20 July 2015

Tightly Curved Swept Blends in Revit Adaptive/Massing Environment

Following on from my last post about 'Unable to Create Form Element' in the Revit Adaptive / Conceptual Massing Environment, here are a few ideas about how you might just solve the problem.

In the conventional family editor, Revit does not have any major problems in creating swept blends along a single path (one spline or arc or line), unless the radius of a curve on the sweep is too small and causes impossible geometry.  For example this simple sweep of a profile along a spline takes a minute or two to create:

In the Adaptive/Conceptual Massing Environment (CME) you have the added ability to loft shapes - to create blends of more than two shapes/profiles.  However, the rules for getting them to work are immensely more complicated, and often quite baffling.  Below is a particular workflow that I was using just to test a process, and it caused all kinds of issues.  Hopefully it might give you some clues as to how to solve similar problems - particularly if the path is more complex.

Creating Swept blends / Lofted Forms along a tightly curved path in CME

  • Place three points 
  • Select the points
  • Create a spline through the points
  • Adjust the spline to have a fairly sharp transition by dragging the middle point
  • Host some new points on spline
  • Host some adaptive profile components on the points
  • Select just the profiles
Select Profiles
  •  Create Form - it fails
  • Try pushing points closer together

  •  Select profiles; then create form - it might work if you are lucky
  •  Maybe you can pull the points back along the curve
  • At some point you get the 'No Entry' sign (circle with line through it), meaning it will not allow you to push the point that far along the spline
  • Try picking the control point for the spline and make it less of a tight curve
  •  Then maybe you can extend form by pushing the points out
  • If it is still not creating the form, you may need the spline to be really gentle to start with before you extend the points out to the ends of the spline
  • Point locations along the spline can be controlled by properties, or you can even make it parametric - using the 'Normalised Curve Parameter'.

  • Intermediate points may also need to move to get a better spread along spline
  •  Then try pulling the spline back to a tighter shape - Revit will most likely allow you to create a much tighter shape than it would originally
  • At some stage you'll notice that the form does not follow the spline, it just creates its own shape by linking the profiles
This may or may not be what you want.
  • If you do want it to follow the spline exactly, your life will be easier:
  • Dissolve the form
  • Select the profiles and the spline
  • Create Form again, and Revit will be much more forgiving - it is more likely to create the form with a tighter curve or one that turns more than 180 degrees on itself.  The obvious difference here is that it knows which order to link the profiles.
  • It uses the spline as a path but only extends between the first and last profiles
If you adjust the spline further, until the shape is too tight it will eventually tell you that it cannot create the form.  I have not figured out yet what the rules are.

What I have figured out is that if you go away for a while and drink a delicious cup of coffee brewed by your local barista (preferably a cappuccino), and come back to try again, you will usually have much more success with pulling the spline around into tighter curves with ends that even extend past each other (but not crossing).

Honestly, it is true that if you are too ambitious with the shapes initially Revit cannot cope.  But try adjusting them later and it works much better.  So the moral of the tale is that Revit gets a boost from caffeine just as much as you do.
More thoughts on lofting and swept blends to follow . . . .
Part 1 - Creating Sinuous Curve Swept Blends in Revit Adaptive/Massing Environment
Part 2 - Creating Revit Swept Blends along sinuous multi-segment paths

Saturday 18 July 2015

Unable to Create Form Element in Revit Massing Environment


Unable to Create Form Element

No doubt anyone who has worked in the Revit Adaptive or Conceptual Massing Environment (CME) has encountered this hated error message, that simply 'cannot be ignored'?

I have recently been the victim of several variations on this error message, some of which were quite puzzling, and even had disastrous results.   Here is a typical scenario of when it might happen, and the sequence of dialog boxes:

Create a framework for a swept blend using profiles on a sweep path
 Refer to 'Creating Swept blends with adaptive profile' and 'Creating Hollow Sweeps' for more details on how to do this:
  • Create a spline in the adaptive/massing environment (external family, or in-place mass family)
  • The spline (or other path) needs to have a fairly tight angle change or else turn through more than 180 degrees over its length in order to demonstrate this issue.
  • Host several points on the spline;   
  • host a profile on the workplane of each point
  • Select each profile component and 'Create Form'
  • Depending on the relationship between the profiles, it might create a lofted form (swept blend), or most likely it will give the following message:
Self-Intersecting Geometry Error
  •  If you click on the 'Expand' button, it tells you nothing except the ID of the form that it cannot create.  
  • It gives you the option to 'Delete Instance', which is not helpful either, as it cannot create the form that it is offering to delete.
  • Try clicking on the 'Show' button and it leads to another series of useless dialog boxes:
  • Click OK to continue
  • Well of course it cannot find a view that shows the form with that ID - because it cannot create the form so it does not exist!  Yes it is sort of consistent with other Revit warnings where it occasionally can find a view showing the offending element - but in this case it is a pointless workflow, and it should not offer us the false hope of showing something it cannot show.

Here is another variation on the error message:
In this case it does not give you any clues about the problem (not even self-intersecting geometry).  At least the Show button is greyed out, because Revit knows it is pointless to try that option.  
No doubt there are plenty of situations where this particular error message might occur, but one I know of is when your profiles have loops inside them - refer to the hollow sweeps post for a solution. 

 (Partial) Solution

Those of you who have some experience with lofting or swept blends in the Massing environment might have already figured out how to solve this issue:
You might have picked up that I only suggested selecting the profiles before create form, but did not include a sweep path - congratulations to those who knew that one.  So, you need to pick the profiles, and the spline (or whatever path) before attempting to create a form.  Revit will then have a much better chance of figuring out what you want to achieve.

However, it still may not work.  In some situations you may not actually want the host framework to dictate the exact form - sometimes you want Revit to directly interpolate between the profiles, which may give a different result.

More on how to achieve this in the next post . . . .

Reorder Profiles Button

  • When creating a form you might be lucky and get a bonus message that seems to offer you a way out:
  • What or where is the 'Reorder Profiles' Button?
  • I spent hours (days, weeks, . . . .) searching for this function in the ribbon, on options bar, in the pantry, under the bed . . . . .
  • Eventually I figured out that someone at Autodesk must have planned to put in a functionality whereby Revit could analyse the order that each of the selected profiles might be changed such that it could actually build the form without self-intersecting geometry - sadly the functionality never eventuated but the dialog message was left hidden in the software. 
  • This functionality does actually exist in some other 3D applications - but not in Revit. . . . .
  • Then one day a few weeks ago, I got this slight variation on the dialog box:
  • Wow - so there is the 'Reorder Profiles' Button:  on the actual dialog box.
  • So, of course I did as I was told, and clicked on it.
  • Bang! Revit imploded and shut down quicker than you can imagine.  No chance to save the files or anything like that.
  • I am not 100% sure about this but it seemed like it actually deleted the Revit file from my hard disk - I can't be certain but I thought I had previously done a 'Save As', and there was no sign of the saved as file.  Maybe we can put that down to the fallibility of human memory?
The moral of the tale is:  If you ever see that 'Reorder Profiles' button, make sure you have a backup of the file before you try it out!

Unable to Create Form Elephant

If you ever see this error message, you are in serious trouble.  But don't worry, all you need to do is to get Marcello Sgambelluri to help out . . . . .